Smoking Upregulates Angiotensin-Converting Enzyme-2 Receptor: A Potential Adhesion Site for Novel Coronavirus SARS-CoV-2 (Covid-19)

Brake, Samuel James; Barnsley, Kathryn; Lu, Wenying; McAlinden, Kielan Darcy; Eapen, Mathew Suji; Sohal, Sukhwinder Singh

in 30% of cases [1] . Rubin et al. found that COPD patients who were prone to viral infections had higher exacerbation rates, more inflammation, and loss of lung function compared to those with existing exacerbating disease conditions [9] . Symptomatology and mortality in influenza-infected smokers were also enhanced [9] . According to the WHO, comorbidities are associated with a high percentage of Covid-19 related deaths [10, 11] . In conjunction with the complications arising from comorbidities in patients who smoke [12] , we put forth the question of whether smoking, smoking-induced health conditions, and comorbidities, in combination, is culminating in a high risk demographic for both contraction of the virus and the severe presentation of Covid- 19. China has a high male smoking rate at around 50% in rural areas and is estimated to be about 44.8% overall [13] . Most of the deaths identified from the epicenter of the Covid-19 outbreak were in men from older age groups and those with underlying conditions such as chronic respiratory disease, cancer, hypertension, diabetes, or cardiovascular disease. The initial age distribution of Covid-19 cases was skewed towards older age groups with a median age of 45 years (IQR 33-56) for patients who were alive or who had an unknown outcome at the time of reporting. The median age of patients who had died at the time of reporting was 70 years (IQR 65-81) as reported by Sun and colleagues [14] . This data was also supported by an early epidemiological study of 99 Covid-19 cases from Wuhan, China [14] .